Central Cord Syndrome

Introduction

The central cord syndrome is the most common form of incomplete cord injury and almost always occurs as a consequence of a traumatic injury. It leads to motor deficits that are more pronounced in the upper extremities as compared to the lower extremities, as well as bladder dysfunction (retention) with varying sensory deficits below the level of injury.[1][2][3] The degree of clinical presentation is quite variable and corresponds to the extent of the injury to the nerve root.

Etiology

Central cord syndrome is an incomplete cord syndrome that results after a hyperextension injury of the cervical spine leading to spinal cord impingement. There are other less common causes, including cervical spondylosis, atlantoaxial instability, tethered cord, osteoporosis, and spinal arthropathies.[4] The damage is caused by impairment of large fibers to conduct signals and consequently results in motor/sensory problems, especially in upper limbs and to some extent in lower limbs. Overall, the amount of function loss is dependent on the extent of the injury to the nerve.[5]

Epidemiology

The central cord syndrome mostly affects males in a bimodal distribution (Falls/motor vehicle collision in those who are young and hyperextension injury in elderly patients with likely underlying spinal disease, including osteoarthritis, or cervical spondylosis). It has a prevalence of 15% to25% in the United States and can occasionally be missed if the patient has mild symptoms at the initial presentation.[6]

Pathophysiology

Central cord syndrome occurs most commonly in those who suffer a hyperextension injury. This usually happens with a forward fall while striking the chin, and having the neck extend backward at the time of the fall. Elderly patients generally have underlying cervical spondylosis (stress defects). This leads to the posterior cord being either compressed or irritated by the posterior ligamentum flavum or anterior cord compression from underlying spondylosis. These two contusion type injuries to the cord can lead to clinical symptoms secondary to edema of the cord at the site of injury. It could also lead to bleeding into the cord at the site of injury, which understandably has a worse prognosis.[7][8][9]

Usually, young patients often suffer from a higher velocity of trauma, leading to cervical spine subluxation/fracture that leads to the above-described compression/contusion/bleeding.

The physical examination findings results due to the compression on the spinothalamic (temperature/pain tract) and the corticospinal tracts of the spinal cord, which can result in motor and sensory deficits. The upper limbs tracts are medial as compared to the lower extremity while sacral segments being the most lateral, So when compression occurs in cervical cords, the central portion becomes more effected then the outer segments due to the external pressure.[8]

History and Physical

The majority of these patients will be elderly and present with symptoms after a fall with hyperextension of their neck. On examination, patients will have more significant strength impairments in the upper extremities (especially the hands) as compared to the lower extremities. Patients often complain of sensory deficits below the level of injury, but this is variable. Pain and temperature sensations are typically affected, but also the sensation of light touch can be impaired. The most common sensory deficits are found in a "cape-like" distribution across their upper back and down their posterior upper extremities. They will often have neck pain at the site of spinal cord impingement.

Urinary retention and priapism can also occur as signs of upper motor neuron dysfunction. The sacral sensation is usually preserved, but the rectal tone should be assessed for the severity of the compression.[10]

Evaluation

All patients with concern for spinal cord injury should have a thorough trauma evaluation performed in the emergency department, and these patients should have cervical immobilization maintained during initial evaluation while obtaining radiologic imaging. Plain radiographs can reveal fractures/dislocations of the cervical spine. Computed tomography of the cervical spine can show the impingement of the spinal canal to some extent. Still, the most sensitive modality to diagnose direct spinal cord impingement is a magnetic resonance imaging (MRI) of the cervical spine.

More severe findings on neurological examination should raise your suspicion for a cervical vertebral fracture. When central cord syndrome is associated with a cervical spine fracture, recovery can be prolonged.[11][12]

Treatment / Management

At the time of diagnosis, high-dose steroids should be considered for administration, preferably within the first eight hours. Corticosteroids suppress the cord edema and help promote blood flow to the area. This recommendation was first made in 1990, and a review of Cochrane in 2012 supports this therapy, but the decision for corticosteroid administration should be discussed with neurosurgical consultants.[13]

Patients have a much better prognosis with the utilization of physical rehabilitation and occupational therapy. The goal of rehabilitation is to preserve the range of motion (ROM) by strengthening the preserved muscular activity, especially in the lower extremities. The physical therapist also focuses on strengthening the core and balance of the patient. Due to the worse symptoms in the upper extremities, using assistive devices (Crutches) for ambulation can be very difficult, so the initial focus will often be on the core and lower limbs. Occupational therapists work with the upper extremities to help retain the ability to perform activities of daily life. Splinting may be utilized when not in therapy to prevent the development of contractures.[14]

Moreover, surgery is rarely indicated. However, neurosurgical and orthopedic physicians should be involved early after diagnosis is made, as occasionally, the amount of cord impingement can progress and worsen. Guidelines published in 2016 recommend that "early surgery be considered as a treatment option in an adult patient with traumatic central cord syndrome."[15]

However, the literature is mixed. Evidence has shown that early surgical treatment has not resulted in neurologic improvement, and numerous other studies showed that delaying surgery in traumatic central cord syndrome may be beneficial where odds of mortality decreased within each day of delay. The thought was to improve the patient's underlying health, especially in older adults, and treat other potential comorbidities before the surgery. Be sure to have the neurosurgical consultants involved early as every patient and as each case is different, and some may do get better with early intervention.[13][15]

Differential Diagnosis

During the evaluation of patient of central cord syndrome conditions which closely mimic CCS should be ruled out including cruciate paralysis and avulsion of cervical roots. Cruciate paralysis is a rare neurological disease involving cervicomedullary junction. The main precipitating factors of cruciate paralysis are mechanical trauma, metabolic disorders, or a post-surgical complication. Typically, the patient of cruciate paralysis presents with bilaterally upper extremity paresis while sparing the lower extremities in the majority of the cases.[16][17] Besides other features, the main differentiating feature in cruciate paralysis is that it affects the selective descending fibers of the corticospinal tract as these fibers decussate at the cervicomedullary junction.[18]

A cervical root avulsion is a severe form of nerve root injury that usually results from the high energy trauma to the neck or ipsilateral arm. Neurological deficits from nerve avulsion range from a mild motor function deficit to complete paralysis that requires surgical correction.[19][20]

Prognosis

The prognosis of central cord syndrome is variable, but the majority of the patients have a neurological recovery to some extent. Young trauma patients and those who seek immediate medical attention have better chances of neurological recovery. Patients of central cord syndrome recover substantial neurological function after the injury; their capacity to walk is recovered in the majority of the cases. However, some of the neurological deficits remain.[21][22] Improvement usually occurs in ascending fashion motor leg function appears to comes first, then bladder control and arms. Hand function appears to comes at last. Abnormal MRI signals can help predict the likelihood of neurological recovery that may occur later in the course of recovery.[23]

Complications

Patients with central cord syndrome are usually prone to a phenomenon called "Autonomic dysreflexia". It is an uncoordinated response of the autonomic system to heart rate and to the vascular walls. This phenomenon usually occurs in the first month of the injury. Common clinical presentations include headaches, flushing, piloerection, increased blood pressure, anxiety, and nausea.[23][5] These symptoms are usually episodic, and they are conservatively managed. Blood pressure monitoring may be required in selective cases for the long term even if the patient is not diagnosed hypertensive. For blood pressure control, nitrates, hydralazine, and labetalol are used, but nitrate should be avoided in patients taking sildenafil.[24]

Neurogenic bladder is another prevalent condition among the patients of central cord syndrome. In central cord syndrome, the sensation of bladder fullness, sphincter function of the bladder, and motor control of the bladder is impaired. Patients experience urgency, spasm, frequency along with urine incontinence.[25] Foley's catheter is used for this purpose, and the majority of the patients regain bladder function. Patients who require long term catheterization, either use a clean intermittent catheter (CIC) or indwelling catheter. A clean intermittent catheter is preferred over indwelling catheters as the rate of infection is much more with an indwelling catheter.[10]

Pressure ulcers are formed as a result of the tissue damage that typically occurs at bony prominences. Around one-third of the patients of central cord syndrome has multiple pressure ulcers. It is usually managed by avoiding immobility, regularly examining the prone parts, application of emollient on the part exposed to friction, use of cushions, and maintaining adequate weight and nutrition.[26]

Deterrence and Patient Education

Patients with central cord syndrome are challenged not only physically but also psychologically as well. Effective communication between interprofessional teams, including neurologists, internists, neurosurgeons, psychiatrists, physical therapists, and nurses, can lead to better outcomes. These patients are prone to depression and suicidal ideation. Furthermore, the lack of motivation can delay the treatment progress and may lead to permanent disability.

Blood pressure can be managed with nifedipine or transdermal nitroglycerin.

Patients with neurogenic bladder may require intermittent self-catheterization but will remain at risk for iatrogenic bladder infections. The majority of the patients will have the return of bladder function after six to eight months.

Neuropathic pain and spasticity are often managed with a regular stretching program, antispasmodic medications. Baclofen is the hallmark of spasticity management (oral initially, but can be placed as an intrathecal pump if severe enough). Patients may require additional medicinal therapy in consultation with a pain specialist or neurologist for their neuropathic pain and spasticity.

Enhancing Healthcare Team Outcomes

The diagnosis and management of central cord syndrome are with an interprofessional team consisting of a neurologist, emergency department physician, neurosurgeon, trauma physician, intensive care unit nurses, physical therapist, and an internist. Once diagnosed, high dose corticosteroids should be administered. Surgery is rarely required. The majority of patients do show recovery with physical therapy, but the recovery is not always complete. Besides, the recovery may take months or even years, and these patients are prone to pressure ulcers, deep vein thrombosis, urinary tract infections, and muscle wasting. The key is to have the surgeons involved early in the care because, in some cases, surgical decompression may help boost recovery. [1][27][28](Level V)